Keyboards are commonly used computer input devices. A computer keyboard comprises a base on which a plurality of keys movably supported by corresponding resilient biasing members. The keys, when struck by a user, move toward the base of the keyboard and deforms the corresponding biasing member to contact and trigger an associated circuit for generating a corresponding signal. The keys have a cap from which a post extends. The post is movably received in a guide channel formed in the keyboard base for guiding the movement of the key. Examples of the conventional key structure are disclosed in Taiwan Patent Publication Nos. 81207039 and 81209527.
A drawback of the conventional key structure is that the stroke of the keys is in general not specifically limited. In other words, the movement of the keys cannot be stopped until they hit the base of the keyboard. Under such a condition, the resilient biasing members of the keyboard that are deformed by the movement of the keys will be subject to a severe impact and deformation thereby shortening the service life thereof. In addition, the strong hit of the post on the associated circuit may cause damage to the circuit.
Furthermore, the post of the cap is loosely received in the guide channel whereby the movement of the post with respect to the guide channel is not well guided leading to unstable operation thereof and a high level of noise. In addition, the loose engagement between the post and the guide channel allows the key to be quickly returned to its un-struck position by the resiliency of the corresponding biasing member of the keyboard the when the striking force is removed. This quick movement also causes a high level noise and potential damage to the keyboard.
Thus, it is desired to provide an improved key structure of a computer keyboard that overcomes the above-discussed problems.